Wheelies rock with a rear hub?
When I get 40wh/mi I am usually crusing at... 30-35mph.
My general guideline is that if you keep the average non-geared hubmotor e-bike to 25mph you should get around 25wh/mi without pedaling.
I don't know how fast it would go at 36v.. I got around max 25mph on 44.4v lipo with a 26" rim. Pedaling would probably get you to 25mph on 36v with the 9c, but you would be looking at about 20mph w/o pedaling.
Play around with that e-bike prediction software some and you'll see some better numbers.